April, ’20] McCOLLOCH: OVIPOSITION OF THE CORN EARWORM 
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than corn, and a study of oviposition on corn is a study of the oviposi- 
tion of the species. 
A single female is capable of depositing from 500 to 2,000 eggs, and 
as high as 570 may be deposited in a single night. The eggs are laid 
singly, and generally only one or two on a plant. In ovipositing, the 
female lays from three to six eggs, then feeds for a short period before 
resuming oviposition, this process being repeated throughout the night. 
Destruction of the Eggs by Natural Agencies 
In the course of these studies, it was found that many natural agen¬ 
cies were responsible for the destruction of the eggs, or at least for their 
removal from the plant within a short time after deposition. The prin¬ 
cipal predaceous enemy of the egg was found to be the common flower- 
bug ( Triphleps insidiosus Say) which often destroyed from 25 to 50 
per cent within 24 hours after deposition. Other predaceous enemies 
were the larvae and adults of the lady beetles Hippodamia convergent 
Guer., H. 13-punctata Linn., H. parenthesis Say, H. glacilis Fabr., 
Adalia hipunctata Linn., Megilla fuscilahris Muls., and Cyclonida 
munda Say. In addition, the larvae of the lace wing ( Chrysopa sp.) 
were often observed feeding on the eggs. A number of insects in feed¬ 
ing cut off many corn silks which bear eggs and these fall to the ground. 
Many eggs are also removed from the plants by winds and beating 
rains. Two parasites, Trichogramma pretiosa Riley and Telenomus 
heliothidis Ash., attack the eggs, but their presence had no influence on 
the egg count. 
Presentation of Experimental Data 
This study of oviposition and silking has been in progress for a period 
of six years, and during that time 128 plants representing four varieties 
of corn have been examined regularly for eggs of the corn earworm, 
and the same number of rows followed with regard to silking. The 
period represents one exceptionally bad earworm year (1914), two years 
of about normal conditions (1913 and 1918), and three years of light 
corn earworm injury (1915, 1916, and 1917). This period is also one 
presenting extremes of climatic conditions from excessive drouth and 
hot winds to high rainfall and moderate temperatures. The detail 
data obtained in these studies are summarized in Table II to show the 
total number of eggs found on each variety of each date of planting and 
in Table III is shown the location of the eggs with relation to the date 
of planting. The data secured from the plantings of July 1 in 1914 
and 1915 are included in the discussion which follows wherever they 
are applicable. There are a number of instances, however, where these 
data are omitted, since they do not represent average conditions. 
